false knock

[aj06bolt12r]

My brother and I have been teaching ourselves to tune with efi live on the truck in the sign below. Right now I'm trying to decide what to do about fals knock. We know its false because we are seeing it with only 10* advance. Obviously the engine doesn't make much power like that. With the knock retard disabled it makes pretty good power. Put down exactly 350rwhp and alittle more tq with 25* timing and about 12.8 afr. I'm sure there is more power to be had with more timing but I'm afraid to push it without the safety of proper KR. I need to pull the intake anyway to replace corroded coolant crossover tube. Would installing knock sensors from a newer truck, say maybe an 04 6.0 solve my issue? I hate to wire in resistors if I'm gonna have intake off anyway. Thanks for any help. Sorry so long winded.

[Frenchy]

If the sensors aren't new, replace them.

[aj06bolt12r]

They are not new... so ok will do. Should-can I buy sensors for a newer truck? I thought I read about the 99 knock sensors being hyper sensitive.

[pl4yboy]

My 08s were hyper sensitive after 30k miles. I was seeing the exact same KR with 30 degrees as I was with 15.

[aj06bolt12r]

My 08s were hyper sensitive after 30k miles. I was seeing the exact same KR with 30 degrees as I was with 15.

Interesting, thanks for the info. I guess later model sensors are not necessarily the answer. How did you solve the problem? Just installed new factory replacement sensors I assume?

[pl4yboy]

Interesting, thanks for the info. I guess later model sensors are not necessarily the answer. How did you solve the problem? Just installed new factory replacement sensors I assume?

I ran 30 degrees of timing and totaled the truck a month later. Solved that issue.

[RedHeartbeat]

Might be best to get a new harness for the sensors just in case your's have corrosion, which is very common.

[farmtruc]

The problem could be the sensors or corrosion.
It's a known issue that moisture enters the ks hole and corrodes the sensor.

It could also be or more likely the 99 PCM and calibration.
99's typically handle 19-23degs of timing at wot before knock appears.

I would skip on the 99 PCM and upgrade to a 2002 PCM and cal.
Problem solved.
We see this quite a bit from the 99 LCMs.

[George C]

before you go changing sensors and etc

check the following, loose converter bolts, loose motor mounts, headers hitting frame, exhaust rubbing frame, heat shields vibrating, excess wobbling of crank pulley.

all of these will cause a KR issue

now does the KR spike and dissappear or does it carry out thru entire run? a spike is false, a carry out is real KR

or do it old school and listen for pinging then back off 2-3 * [this was the method used before knock sensors] in some cases add timing till it quits making power then back it off 2-3*

[aj06bolt12r]

Quick, when on I will see KR almost any and all rpm and any throttle % over Maybe 20%. It does this with 93 octane and 2 bottles of booster on flat ground and in 20* weather. We tried locking the timing in at 10* and still saw KR as soon as I started taking off. I know converter boots are tight, haven't been installed over a month. Headers touch nothing, no heat sheilding left on exhaust. I though my tip might have been touching my hitch so I insulated it with rubber. No difference. I've never heard this truck make any pinging. I know what it sounds like for sure. But the exhaust is so loud I don't know if I would hear it if it did.